Hydraulic buffer assembly

ABSTRACT

A hydraulic buffer assembly for use in a paint gun includes a sealed housing having first and second ends and an interior including a chamber containing a hydraulic fluid. A piston assembly including at least one piston rod and a piston head is axially movable through the interior of the housing, wherein the piston head includes at least one orifice through which hydraulic fluid flows when the piston assembly is moved under load. The buffer assembly is configured to decrease or slow the firing rate of an automatic paint gun.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 15/583,150, entitled: Hydraulic Buffer Assembly, filed May 1,2017, which claims priority under relevant portions of 35 U.S.C. § 119and 37 CFR § 1.53 to U.S. Patent Application No. 62/330,455, entitled:Hydraulic Buffer Assembly, filed May 2, 2016, the entire contents ofeach application are herein incorporated by reference.

TECHNICAL FIELD

This application is generally directed to the field of buffer assembliesand more specifically to a hydraulic buffer assembly that is preferablyconfigured for use in an automatic or semi-automatic paint ball gun ormarker. The hydraulic buffer assembly produces a time delay or lag inorder to effectively control the firing rate of the paint ball gun.

BACKGROUND

Paint ball guns or markers are commonly used for recreational purposesas well as for police and military training. Typically, a paint ball gunlaunches a projectile under force, typically using an expanding gas suchas compressed air or carbon dioxide, at a muzzle velocity ofapproximately 90 m/sec (about 300 ft/sec). Upon impact with a target ofinterest, the projectile (paint ball) releases a stored quantity ofbrightly colored paint. Greater velocities can be achieved, but havebeen regulated due to safety concerns. Over time, these devices havebecome fairly sophisticated and complex, wherein semi-automatic andautomatic versions have been developed, and in which the firing or burstrate has also seen significant increases. For example, some paint gunsare capable of firing up to thirty (30) rounds per second.

Specific regulations in various states in the United States, as well asdifferent foreign countries dictate that the firing rate of automaticpaint ball guns or markers must be controlled within specific maximums,in the interest of safety. Accordingly, there is a need in the field toprovide a buffer assembly that can be incorporated into new or existingpaint guns or markers in order to slow the firing rate of an automaticpaint gun within the promulgated standards. Though electronic versionshaving complex circuitry have been developed, to date, Applicant isunaware of a hydraulic buffer being configured for incorporation orinclusion within a paint ball gun.

BRIEF DESCRIPTION

According to a first aspect, there is provided a buffer assembly forcreating a time delay upon receipt of an inputted load or force whilemaximizing the receipt of a return force. The apparatus includes ahousing having a first end and a second end with a piston assemblyextending within an interior of the housing. The piston assemblyincludes an orificed piston head that moves a contained hydraulic fluidbased on the stroke of the piston upon receipt of an applied load, themovement of hydraulic fluid creating a time delay to the inputted loador force. The piston assembly also includes a check valve for fastreturn of the piston assembly in the opposite direction so that thebuffer assembly is ready to provide a time delay for the next firingcycle. In at least one version, the above assembly can be used within apaint ball gun and more specifically, an automatic paint ball gun forpurposes of controlling firing rate.

According to one version, the piston assembly includes a first pistonrod and a second piston rod secured together axially, as well as a glidering and a seal retainer, each disposed between the piston head and aninterior wall of the housing.

In at least one embodiment, the glide ring and seal retainer includethrough openings aligned with one another and the orifices of the pistonhead that permit the passage of hydraulic fluid when the piston assemblyis moved through the interior of the housing under load.

The first piston rod can include a narrowed end portion that is securedwithin an opening of the second piston rod and in which the secondpiston rod is secured to the seal retainer, the seal retainer beingconfigured for movement with the piston assembly.

The glide ring is preferably disposed between the piston head and theseal retainer and is disposed for movement based on movement of thepiston assembly. According to one version, the buffer assembly includesa pair of quad rings that are fixedly secured within the interior of thehousing within spaced regions, each of the spaced regions being smallerthan the quad rings and therefor compressing same.

In at least one version, the orifices of the piston head include atleast one check valve and in which the seal retainer has an outerdiameter that is smaller than an inner diameter of the housing, therebycreating an annular space for moving hydraulic fluid.

The piston head can be defined with an outer diameter that is smallerthan an inner diameter of the housing, thereby creating an annular spacefor moving hydraulic fluid in addition to the orifices, when the atleast one check valve is open.

The glide ring can be defined by an outer diameter that almost matchesthe inner diameter of the housing to act as a seal on the inner diameterof the housing, the glide ring including an opening to permit thepassage of hydraulic fluid for buffering purposes.

According to another aspect, there is provided a method for slowing thefiring rate of an automatic paint gun, the method comprising:

providing a housing secured within the paint gun having first and secondends and an interior including a chamber containing a hydraulic fluid;

providing a piston assembly including a pair of piston rods and a pistonhead that is axially movable through the interior of the housing, thepiston head including at least one orifice; and

applying a load attributable to firing the paint ball gun to a firstpiston rod, causing hydraulic fluid to be moved through the orifices ofthe piston head and damping the assembly by controlling the velocity ofthe buffer when being stroked in one direction during the firing andreturn cycle of the gun, causing a time delay and thus slowing thefiring rate.

In one version, the piston assembly includes the pair of piston rodsthat are attached to one another at opposing ends, in which the pair ofpiston rods are configured to move in tandem. A piston head attached toone of the piston rods includes a set of orifices through whichhydraulic fluid moves when the piston head is advanced.

One advantage realized by the herein described design is that the firingrate of an automatic firearm, such as a paint ball gun, can be moreeffectively and mechanically controlled, as opposed to electronic meansas conventionally employed, the latter being less reliable, more complexand expensive and also requiring electric power.

Another advantage of the herein described design is that the bufferassembly is sufficiently compact to fit within a very small area of thegun. As a result, the overall footprint of the gun is not compromised oreffected.

These and other features and advantages will be readily apparent fromthe following Detailed Description, which should be read in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features and advantages of the present invention will becomemore apparent when taken in conjunction with the following descriptionand drawings wherein identical reference numerals have been used, wherepossible, to designate identical features that are common to thefigures, and wherein:

FIG. 1 is a side elevational view of a hydraulic buffer assembly inaccordance with an embodiment;

FIG. 2 is the side elevational view, taken in section, of the hydraulicbuffer assembly of FIG. 1 in a first or expanded position;

FIG. 3 is the side elevational view of FIG. 2 of the hydraulic bufferassembly in a second or compressed position;

FIG. 4 depicts a buffer assembly shown schematically in connection witha paint gun; and

FIG. 5 is a side elevational view of a paint gun that is configured foruse with a buffer assembly in accordance with an embodiment.

DETAILED DESCRIPTION

The following discussion describes a hydraulic buffer assembly orapparatus that is made in accordance with a specific embodiment. It willbe understood, however, that various modifications and variations can bemade within the ambits of the herein described concept. In addition,certain terms such as “first”, “second”, “inner”, “outer”, “above”,“below”, “left”, right”, “interior”, “exterior”, and the like are usedthroughout the course of discussion in order to provide an suitableframe of reference with regard to the accompanying drawings. It shouldbe noted, however, that these terms, unless specifically indicatedotherwise, are also not intended to narrow the scope of the invention.In addition, similar parts described in the various views are labeledwith the same reference numbers for the sake of clarity andunderstanding.

With reference to FIG. 1, there is depicted a hydraulic buffer assembly100 defined by a substantially cylindrical assembly housing 104 havingrespective first and second ends 108, 112 and a center axis 110. Aclevis or similar connecting member 116 is attached relative to thefirst end 108 of the housing 104. According to this describedembodiment, the clevis 116 includes a center hole or opening 120.

Referring to FIGS. 1 and 2, the housing 104 is defined by an interior105 wherein the clevis 116 is fixedly attached to a piston assembly andmore specifically an extending end of a first piston rod 124. A setscrew 129 is fitted within respective end openings of the clevis 116 andthe first piston rod 124, wherein the end of the clevis 116 includes anannular shoulder 117 that engages the end of the first piston rod 124 toreliably position or seat same.

The interior 105 of the assembly housing 104 is substantially hollow andis sized and configured to retain a plurality of components of theherein described hydraulic buffer assembly 100. A retainer 128 isdisposed in the interior 105 of the assembly housing 104 at the firstend 108. The retainer 128 includes a center opening 130 that is sizedand configured to receive the first piston rod 124 and in which an outerwall of the retainer 128 is pressed flush with an interior or inner wall107 of the assembly housing 104. Adjacent the retainer 128 and containedwithin the housing interior 105 is a front bearing assembly 135 that issealingly and fixedly engaged with the inner wall 107 of the assemblyhousing 104.

According to this embodiment, the bearing assembly 135 includes anannular recess 137 that is sized and configured to retain a sealing ring138, the latter preferably being elastomeric in nature which is disposedwithin the recess 137 and in sealing contact with the inner wall 107 ofthe assembly housing 104. The bearing assembly 135 further includes acenter opening 139 that is sized and configured to permit the passage ofthe first piston rod 124 and in which the bearing assembly 135 otherwiseessentially fills the interior space of the assembly housing 104 at thefirst end 108, with the exception of a recessed portion 141 adjacent theretainer 128 that receives a quad ring 145.

As shown in the sectioned view according to FIGS. 2 and 3, the recessedportion 141, the outer wall of the first piston rod 124, and an interiorwall of the retainer 128 combine to define a spaced region that fullyencloses the quad ring 145. According to this embodiment, the size ofthis latter defined spaced region is preferably smaller than the quadring 145 in order to create an interference fit and induce compression.

The piston assembly further includes a piston head 150 that is securedto a shoulder of the first piston rod 124, the latter being axiallymovable along with the first piston rod 124 and attached fixedlythereto. According to this embodiment, the piston head 150 is defined bya cylindrical body including an outer diameter that is smaller than thatof the inner surface 107 of the housing 104, thereby forming an annulargap. The piston head 150 further includes a center opening 154 thatreceives a narrowed diametrical portion 158 of the first piston rod 124that further passes thorough an opening 164 formed in an adjacent glidering 162. An expanded portion of the piston head 150 retained againstthe shoulder of the first piston rod 124 includes a set of axiallydisposed orifices 153. According to this embodiment, the orifices 153are radially disposed beyond the first piston rod 124 such that theorifices 153 extend through the entirety of the expanded portion. Anarrowed portion of the first piston head 124 extends axially from theexpanded portion, the latter having a smaller outer diameter.

Still referring to FIGS. 2 and 3 and according to this embodiment, theglide ring 162 has an outer diameter that almost matches the innerdiameter of the assembly housing 104 and in which the narroweddiametrical portion 158 of the first piston rod 124 further extendsthrough the formed center opening 172 of a seal retainer 170 adjacentthe glide ring 162. The seal retainer 170 receives the smallerdiametrical portion 158 of the first piston rod 124, the latter passingthrough the formed center opening 172. In addition and according to thisembodiment, the seal retainer 170 includes a recessed portion 174 on afacing surface closest to the second end 112 of the housing 104 that issized to receive the end of a separately attached second piston rod 190,as well as an annular passage 176.

According to this embodiment, the second end 112 of the assembly housing104 includes a spacer 180 that is press fitted to the inner surface 107of the assembly housing 104. The spacer 180 is fixedly attached to theassembly housing 104 and is defined by a center opening 184 throughwhich extends the second piston rod 190, the latter being part of thepiston assembly and having an end opening 194 that is sized toaccommodate the end of the narrowed diametrical portion 158 of the firstpiston rod 124. The piston rod 190 which is also axially movable extendsthrough an opening 109 formed in the interior wall 107 of the housing104 and extends into a chamber 200 filled with a hydraulic fluid, suchas a silicone fluid.

A quad ring 210 is disposed within a fixed spaced region 214 definedbetween the spacer 180, the outer surface of the second piston rod 190,and an interior wall of the housing 104. As in the first end 107, thedefined spaced region is smaller than the outer dimensions of the quadring 210, thereby creating an interference fit and compression of thefitted quad ring 210. The quad rings 145, 210, which as previously notedare preferably compressed into their respective cavities form seals forthe hydraulic chamber 200 within the interior of the assembly housing104. A rear bearing 215 is housed within the spacer 180 to support thesecond piston rod 190.

The overall operation of the hydraulic buffer assembly 100 is furtherdiscussed with reference to FIGS. 2 and 3. The assembly 100, as shown insection, is depicted in an initial or extended position according toFIG. 2. An axial load is applied or otherwise imparted to the clevis 116(see arrow 191, representative of the movement of the bolt (not shown)of the paint gun (not shown)) that causes the attached first piston rod124 and the clevis 116 in unison to move toward the second end 112 ofthe assembly housing 104. The first piston rod 124 axially advancesthrough the front bearing assembly 135 wherein the orificed piston head150 is also caused to move axially toward the second end 112 of thehousing 104. The orificed piston head 150 sequentially engages the glidering 162 and seal retainer 170, wherein the second piston rod 190 isaxially advanced through the second end 112 of the housing 104 to thecompressed position shown in FIG. 3. During compression, the glide ring162 moves to seal against the front face of the piston head 150, asshown in FIG. 2. The glide ring 162 acts as a check valve.

The contained hydraulic fluid is moved during this part of the operationthrough the orifices 153 of the piston head 150. Overall, the hydraulicfluid is first guided through a path through the defined annularpassages 176 of the seal retainer 170 and around the outside diameter ofthe seal retainer 170, through the inner opening 164 of the glide ring162. The fluid is then moved through the orifices 153, but only as aresult of the glide ring 162 having sealed against the front face of thepiston head 150, thereby sealing the annular gap formed on the pistonhead 150 between the outer surface of the piston head 150 and the innersurface of the housing 104. At the end of the stroke, the seal retainer170 engages the interior wall 107 of the housing 104, as shown in FIG.3, with an end of the second piston rod 190 outwardly extending from thesecond end 112 of the housing 104.

With continued reference to FIGS. 2 and 3 and according to thisembodiment, a restoring force can be provided to the herein describedbuffer assembly 100. For example, a spring (not shown) can be configuredto engage the end of the second piston rod 190 in order to drive thesecond piston rod 190 and the attached seal retainer 170 against thepiston head 150 toward the first end 108 of the assembly 100. Hydraulicfluid contained within the defined chamber 200 is moved around theannular gap and through the orifices 153 formed in the piston head 150without the delay previously caused by the check valve (i.e., checkvalve is open) as the glide ring 162 engages the inner wall of thehousing 104. The hydraulic fluid is moved through the inner opening 164of the glide ring 162 and then through the annular passage 176 of theseal retainer 170, with the first piston rod 124 and the clevis 120being returned to the initial position of FIG. 2. According to thisembodiment, the overall stroke of the depicted buffer assembly 100 isabout 0.120 inches, although this parameter can be suitably varieddepending on the application and paint gun. As such, the clevis 116 canbe quickly moved from the compressed position of FIG. 3 to the initialextended position of FIG. 2, as aided by the opened check valve whereinthe contained hydraulic fluid is more quickly moved to advance thehydraulic buffer assembly 100.

An exemplary representation of a buffer assembly 100 as used in a paintgun is shown schematically in FIG. 4, the paint gun 300 being shown morecompletely in FIG. 5. The buffer assembly 100 is extremely compact andtherefore takes up little room. One preferred location of the bufferassembly 100 is shown in phantom in FIG. 5. With reference to FIG. 4 andaccording to this schematic representation, the bolt assembly 304 of thepaint gun 300 is translatably movable per arrow 318 within a definedchamber and biased by means of a bolt spring 308. The bolt assembly 304,according to this embodiment, is mounted in parallel with the bufferassembly 100 by means of a pivoting assembly 316. According to thisembodiment, one end of the pivoting assembly 316 is maintained incontact with a portion of the movable bolt assembly 304. The remainingend of the pivoting assembly 316 is rotatably attached to the clevis end116, FIG. 2, of the buffer assembly 100 and the contained movable pistonassembly, see arrow 321. A tension return spring 320 having one endoperatively coupled to the buffer assembly 100 is configured forsupplying the restoring force thereto. The remaining end of the tensionreturn spring 320 and the bolt spring 308 are fixedly attached tostructure within the paint gun 300.

With reference to FIGS. 1-5, the translatable movement of the boltassembly 304 between its firing and return cycles creates correspondingmovement of the attached pivoting assembly 316 and therefore the bufferassembly 100 between the initial extended position of FIG. 2 and thecompressed position of FIG. 3. Damping occurs during the compression ofthe buffer assembly 100, while free flow of the hydraulic fluid occursas the buffer assembly 100 is moved to the extended position as aided bythe tension return spring 320. As a result, the firing rate of the paintgun 300 upon depression of the trigger 330 can be effectivelycontrolled.

PARTS LIST FOR FIGS. 1-5

-   100 hydraulic buffer assembly-   104 housing, assembly-   105 interior, housing-   107 interior wall, housing-   108 first end, housing-   109 opening-   110 axis, housing-   112 second end, housing-   116 clevis or connecting member-   117 shoulder, clevis end-   120 center hole or opening-   124 first piston rod-   128 retainer-   129 set screw-   130 center opening, retainer-   135 bearing assembly-   137 recess-   138 sealing ring-   139 center opening, bearing assembly-   141 recessed portion, bearing assembly-   145 quad ring-   150 piston head-   153 orifices, piston head-   154 center opening-   158 narrowed diametrical section-   162 glide ring-   164 inner opening, glide ring-   170 seal retainer-   172 center opening, seal retainer-   174 recessed portion-   176 annular passage, seal retainer-   180 spacer-   184 center opening, spacer-   190 second piston rod-   191 arrow-   194 opening, second piston rod-   200 chamber, hydraulic-   210 quad ring-   214 fixed space region-   215 rear bearing-   300 paint gun-   304 bolt assembly-   308 bolt spring-   316 pivoting assembly-   318 arrow, movement-   320 tension return spring-   321 arrow, movement-   330 trigger

The invention is inclusive of combinations of the aspects describedherein. References to “a particular aspect” (or “embodiment” or“version”) and the like refer to features that are present in at leastone aspect of the invention. Separate references to “an aspect” or“particular aspects” or the like do not necessarily refer to the sameaspect or aspects; however, such aspects are not mutually exclusive,unless so specifically indicated or as are readily apparent to one ofskill in the field. The use of singular or plural in referring to“method” or “methods”, and various components of the herein describedassembly and the like is not intended to be overly limiting. The word“or” is used in this disclosure in a non-exclusive sense, unlessexplicitly noted.

This invention has been described in detail with particular reference tocertain aspects thereof. It will be readily apparent and understood thatvariations, modifications, and combinations can be effected by a personof ordinary skill within the intended scope of the invention and inaccordance with the following claims.

1. (canceled)
 2. A method for manufacturing a buffer assembly, themethod comprising: providing a buffer assembly housing having a sealedchamber filled with a hydraulic fluid; disposing a piston assemblywithin the buffer assembly housing, the piston assembly comprising: apiston rod connectable to a structure under load; and a piston headattached to the piston rod, in which the piston head is movable throughthe sealed chamber and has a diameter smaller than an inner surface ofthe chamber, the piston head further having at least one axial orifice;and providing a glide ring on the movable piston head, the glide ringhaving a diameter that is substantially equal to the inner surface ofthe chamber, wherein the glide ring prevents movement of hydraulic fluidaround the piston head when the piston head is moved in a firstdirection and in which hydraulic fluid is permitted to flow around thepiston head, as well as through the at least one axial orifice, when thepiston head is moved in a second direction opposite the first direction.3. The method according to claim 2, in which a damping force is impartedto the connected structure when the piston head is moved in the firstdirection that slows the movement of the piston head and connectedstructure.
 4. The method according to claim 3, in which one end of thepiston rod extends outside of the sealed chamber and is connectable toan automatic paint gun in order to control the firing rate thereof. 5.The method according to claim 2, further comprising: providing the glidering with at least one axial orifice aligned with the at least one axialorifice of the piston head.
 6. The method according to claim 2, furthercomprising: movably disposing the glide ring on an extended portion ofthe piston head.
 7. The method according to claim 2, further comprising:providing a check valve in the at least one axial orifice of the pistonhead.
 8. A method for slowing the firing rate of a firearm, comprising:coupling the firing mechanism of the firearm to one end of a piston rodextending from a sealed chamber filled with a hydraulic fluid, causing apiston head linked to the piston rod to move through the sealed chamberin a first axial direction upon firing of the firearm, the piston headhaving a diameter that is smaller than an inner surface of the sealedchamber and in which hydraulic fluid moves through the at least oneaxial orifice, but is prevented from moving around the piston head whenthe piston head is moved in the first axial direction, thereby creatinga damping force that slows the coupled firing mechanism, and uponapplication of a restoring force, causing the piston head to be moved ina second axial direction opposite that of the first axial direction inwhich hydraulic fluid moves around the piston head, as well as throughthe at least one axial orifice of the piston head.
 9. The methodaccording to claim 8, further comprising: providing a glide ringconfigured to move with the piston head, the glide ring having adiameter essentially matching that of an inner surface of the sealedchamber wherein the piston head has a smaller diameter than diameter ofthe glide ring.
 10. The method according to claim 9, further comprising:providing at least one axial orifice in the glide ring and aligning theat least one axial orifice of the glide ring with the at least one axialorifice of the piston head.
 11. The method according to claim 9, furthercomprising: providing a seal retainer, and positioning the glide ringbetween the seal retainer and the piston head.
 12. The method accordingto claim 9, in which the piston head is defined by an extended portion,wherein the glide ring is movably disposed on the extended portion. 13.The method according to claim 11, further comprising: providing the sealretainer with a diameter that is smaller than the diameter of the glidering, creating an annular space for movement of hydraulic fluid.
 14. Amethod as recited in claim 8, in which the firearm is an automatic paintgun.
 15. A method for controlling the firing rate of an automatic paintgun, the method comprising: coupling the firing mechanism of theautomatic paint gun to one end of a piston rod extending from a bufferhousing having a sealed interior chamber filled with a hydraulic fluid,causing a piston head connected to the piston rod to move through thesealed interior chamber in a first axial direction when the automaticpaint gun is fired, the piston head having a diameter that is smallerthan that of an inner surface of the sealed interior chamber and inwhich hydraulic fluid moves through the at least one axial orifice, butis prevented from moving around the piston head when the piston head ismoved in the first axial direction, and upon application of a restoringforce, causing the piston head to be moved in a second axial directionopposite that of the first axial direction in which hydraulic fluidmoves around the piston head, as well as through the at least one axialorifice of the piston head.
 16. The method according to claim 15,further comprising: attaching a movable glide ring to the piston headwithin the buffer housing, the glide ring having a diameter thatessentially matches that of an inner surface of the sealed interiorchamber.
 17. The method according to claim 16, in which the glide ringincludes at least one axial orifice aligned with the at least one axialorifice of the piston head.
 18. The method according to claim 16,further comprising: disposing the glide ring on an axially extendingportion of the piston head.
 19. The method according to claim 16,further comprising: disposing a seal retainer within the buffer housing,in which the glide ring is disposed between the seal retainer and thepiston head.
 20. The method according to claim 15, further comprising:mounting the buffer housing in parallel with a bolt assembly of theautomatic paint gun.
 21. The method according to claim 20, furthercomprising: providing a pivoting assembly interconnecting the bufferassembly to the bolt assembly.